I am not too much up on Kubota, but I sure love my fancy seat that came with my New Holland. There is a major difference from the other one I had. This one you can move back and forth and is much more plush than my other one. Also no one would ever be able to talk me into anything other than Hydrostatic. If you do a lot of mowing and FEL work hydro is a must.
Don't make the same mistake I made. I bought a TC21D and found it was not want I wanted. Bothered the living day lights out of me and finally went back and got a TC29D. Now I am a happy camper. I don't know if Kubota has supersteer, but if a lot of mowing that really is nice also. If Kubota is on your mind then I wouldn't worry too much about having supersteer but seriously think about that seat and hydro.
murph
Murph